This is a planning grant proposal to support development and refinement of the procedures for a multicenter, randomized clinical trial of the safety and efficacy of contact lens management of keratoconus. Keratoconus is a bilateral, asymmetric corneal disease which results in thinning and distortion of the corneal apex. It is typically associated with marked irregular corneal astigmatism and is characterized by axial corneal scarring as the disease progresses. Its average annual incidence rate is estimated at 2 per 100,000 population (Kennedy et al., 1986). In the United States, currently employed management methods include spectacle correction, rigid contact lens wear to improve vision by correcting the corneal irregularity, penetrating keratoplasty and epikeratoplasty. The proposed study, Contact Lens Evaluation in Keratoconus (CLEK), will examine the effects of two different contact lens fitting methods: a flat fitting method where the contact lens actually touches the corneal apex, and a steep fitting method where the contact lens clears the corneal apex. Although there is some evidence that flat fitting lenses may result in increased corneal scarring in keratoconus (Korb et al. 1982), most contact lens practitioners fit with a flat fitting method as it is simpler to fit and patients appear to prefer the comfort of the flatter fit. We propose a randomized clinical trial to compare the safety (corneal scarring) and efficacy (visual acuity and wearing time) of flat and steep contact lens fitting methods in keratoconus.